Comparison of Quasistatic Bumper Testing and Dynamic Full Vehicle Testing for Reconstructing Low Speed Collisions

It has been proposed that low speed collisions in which the damage is isolated to the bumper systems can be reconstructed using data from customized quasistatic testing of the bumper systems of the involved vehicles. In this study, 10 quasistatic bumper tests were conducted on 7 vehicle pairs involved in front-to-rear collisions. The data from the quasistatic bumper tests were used to predict peak bumper force, vehicle accelerations, velocity changes, dynamic combined crush, restitution, and crash pulse time for a given impact velocity. These predictions were compared to the results measured by vehicle accelerometers in 12 dynamic crash tests at impact velocities of 2 - 10 mph. The average differences between the predictions using the quasistatic bumper data and the dynamic crash test accelerometer data were within 5% for bumper force, peak acceleration, and velocity change, indicating that the quasistatic bumper testing method had no systematic bias compared to dynamic crash testing. The root mean square differences were 21% - 23% for peak vehicle accelerations and 12% for vehicle velocity changes. The root mean square differences when comparing crash test accelerometer data from one vehicle to the other using Newton's second law and assuming the vehicles to be rigid bodies were 11% - 18% for all parameters. We conclude that quasistatic bumper testing is an effective tool for reconstructing low speed collisions because it replicates the results of dynamic full vehicle crash testing with good accuracy.